A tilt-in-space wheelchair provides the necessary change in position for the user who cannot effectively shift their body weight or change their position. These individuals are at a higher risk for skin breakdown and their sifting tolerance is compromised. A typical tilt-in-space wheelchair frame tilts up to 45 degrees from horizontal while maintaining the same back to seat angle. This feature provides a change in position for those people who have a difficult time maintaining their pelvic, trunk, and head position against gravity for extended periods of time. This feature can also assist in preventing postural collapse which puts them at risk for respiratory or digestive complications. Individuals who suffer from postural hypotension also benefit from tilt-in-space chairs.
Despite the fact that the wheelchair industry offers several models with a tilting seating system, no manual wheelchairs currently on the market are designed so that the user can tilt independently, that is, none can be tilted without the assistance of an attending caregiver. Tilt wheelchairs were designed so that the user's body can be angled at various degrees so that pressure points are redistributed and their upper body can be positioned for optimal posture and comfort. The existing manual tilt wheelchairs have to be activated by a caregiver with the control located in the back of the chair, or to the side, out of the users reach. They are also designed with the armrest and seat attached to each other, therefore, the design does not give the user a place to push and pull from to activate the tilt feature.
The average wheelchair user spends 8-14 hours in their wheelchairs daily. These individuals who spend these extended hours in a static upright position often end up needing additional medical treatments. They are at risk for pressure ulcers, skin tears, skeletal deformities (specifically kyphosis or “C” curve posture), impaired respiration and digestion from forward flexed postures, joint contractures, pain and discomfort, agitation, decreased mobility, and falls, which can result in injuries.
For the average, able-bodied person, relief from discomfort during prolonged sitting is made by frequent, small, unconscious body adjustments that maintain comfort levels. For persons with physical disabilities and generalized muscle weakness, the discomfort and pain from daily wheelchair sitting can be chronic and debilitating. In addition to the potential for developing decubitus ulcers, many people in this population experience intolerable periods of discomfort and pain, which can lead to reduced participation in daily activities including, work, education, and recreation, and retrieval. (D. Hobson & Barbara Crane: State of the Science White Paper on Wheelchair Seating Comfort Feb. 9, 2001)
According to the National Pressure Ulcer Advisory Panel (NPUAP) the treatment costs for patients who developed ulcers were estimated to be as much as $6 billion per year. In elderly populations and in those who are institutionalized, pressure ulcers are one of the most costly diseases to treat. These ulcers add an estimated burden of over $1 billion in expenditures and an additional 2.2 million Medicare hospital days to the United States healthcare system. The bottom line alone, without considering the cost of human suffering, demonstrates the importance of preventing pressure ulcers.
Accordingly, it would be advantageous to have a manual wheelchair with a user controlled seat tilt mechanism that can be readily operated by the user while sitting in the wheelchair without the need for assistance of a caregiver so as to allow the user to make desired adjustments to the angular orientation of the seat of the wheelchair.